Whatman qualitative filter paper is a type of filter paper designed for general purposes. These filters, made from cellulose fibers, are constructed from high-quality cotton that contains the maximum amount of alpha cellulose. Alpha cellulose is the most stable form of cellulose with the highest degree of stable polymerization. Cellulose paper made from a high percentage of alpha cellulose, such as Whatman paper, is an indicator of high quality and strength. The quality grade of filter paper is determined based on various properties, including particle retention, thickness, and weight.